Vacuum gripper systems make use of the Venturi effect for generating the suction needed for gripping and handling articles by means of suction cups that receive the generated vacuum. Such vacuum generators or vacuum pumps, sometimes referred to as “ejectors”, are in the form of boxes or modules that are fed with a gas under pressure that, on passing through an internal flow throat, creates suction in a chamber at the throat, and thus creates the necessary vacuum. Each module thus has an inlet orifice for gas under pressure, a suction orifice for connecting to a gripper member, and an outlet orifice for the expanded gas plus the gas that has been sucked in.
Such boxes or modules are also fitted with control means (solenoid valves), monitoring means (pressure gauges), or regulation means, incorporated in each module and serving firstly to execute commands delivered to each module over a fieldbus associated with the machine in order to perform a gripping cycle delivered by a programmable automaton and secondly to optimize the operation of each pump depending on the vacuum needs encountered and on how they vary while the gripper is in operation. This management of the operation of each pump makes it possible to adjust energy consumption to match requirements as closely as possible, where energy consumption in this situation is the consumption of gas under pressure.
These vacuum pumps are adjusted at the location of each pump, which. possesses a front face for communication with man/machine dialog elements such as pushbuttons in order to set setpoint values and to display elements for viewing useful parameters during operation.
In a gripper of that type, locating the vacuum generator in the vicinity of the or each suction cup is necessary or desirable in order to optimize the operation of the equipment in terms of energy savings and response times, for example. It is then difficult or even. dangerous to access each of these generators during the operation of vacuum gripper and handling machines in order to specify the level of vacuum required for each application of the machine (e.g. as a function of the porosity of the material that is to be held and moved) or in order to remedy a defect observed in the operating cycle of such-and-such a suction cup of the gripper.